Thank you gentlemen, this is indeed very helpful. I would primarily be using the phone in Peru and while travelling globally, but it would be my personal (not work) phone in the US, so I am interested in ensuring that it would work there also.
I am not particularly concerned about using the phone while in China - I have always used all of my usual apps with a VPN with nary a hiccup, but must admit I am not certain about whether I carried out any updates.
And a special thank you for the update on the new Huawei coming out.